This invention relates to a method and also to an associated apparatus for examining structural members for purposes of detecting hidden defects.
Architectural and vehicular structural members such as bridge girders, columns, floor and roof support beams, airplane wings, and other architectural and vehicular stress-bearing members can suffer failure arising from invisible defects. Not infrequently, stress fractures and fatigue cracks originate internally to a support member and are not detectible even by the most sensitive and rigorous of existing testing techniques. Such defects may result in dangerous, even fatal, accidents irrespective of the diligent care taken by maintenance personnel.
It is not uncommon for aging structures to be destroyed or discarded for fear of structural failure even though the structures may still have many years of useful life, unbeknownst to the owners. This premature retirement of buildings, bridges, planes, train cars, etc., is generally a waste of public and private assets and thus contributes to rising costs and depleting resources.
Even where architectural and vehicular assets are maintained, structural investigations are time consuming and expensive. The necessary expense is particularly evident where the investigated structures must be disassembled and transported to testing facilities. Detecting hidden defects without disassembly of the structures is even more difficult when the structures cannot be disassembled, for example, in the cases of buildings and bridges.